Effects of a high-fat diet on the bone structure of Wistar rats: a systematic review.

CONTEXT: Saturated fats found in diets known as high-fat, cafeteria, or Western diets appear to have a negative effect on bone structure; however, few studies have focused on investigating this association, and the data available in the literature remain controversial. OBJECTIVE: The aim of the current review was to investigate the effects of a high-fat dietary intake on the bone structure of Wistar rats. DATA SOURCES: A search for articles was carried out in the Pubmed/MEDLINE, Web of Science, Embase, and Scopus databases. DATA EXTRACTION: In total, 447 articles were found in the initial search; 5 articles were included in the systematic review, after application of the exclusion criteria. DATA ANALYSIS: The review was guided by the PICOS strategy and based on the PRISMA protocol for animal reviews. CONCLUSION: High-fat diets appear to affect bone structure of Wistar rats. Diet composition and exposure time are the factors determining the strength of the effect.

El peroné: mal alumno, pero buen profesor. (¿Qué tiene prioridad biológica: la integridad, o la supervivencia?) / Fibula: a bad pupil but a good profesor. (What comes first, integrity or survival?)

La concepción original del mecanostato como un regulador de la rigidez estructural ósea orientado a mantener un determinado 'factor de seguridad' en todos los esqueletos parece no corresponder por igual a cualquier hueso y para cualquier tipo de estímulo. Hemos descubierto que la estructura cortical diafisaria del peroné humano manifiesta un comportamiento ambiguo del sistema, referido al uso del pie. La diáfisis peronea, además de ser insensible al desuso, se rigidiza, como sería de esperar, por entrenamientos en disciplinas deportivas que rotan o revierten el pie (hockey, fútbol, rugby); pero, llamativamente, se flexibiliza en su mitad proximal por entrenamiento en carrera larga, que optimiza el rendimiento del salto que acompaña a cada paso. La referida rigidización robustecería la región peronea de inserción de los músculos que rotan o revierten el pie, favoreciendo la locomoción sobre terrenos irregulares o 'gambeteando', propia de especies predadoras como los leopardos. La 'inesperada' flexibilización proximal, pese a reducir la resistencia a la fractura por flexión lateral (poco frecuente en el hombre), favorecería la absorción elástica de la energía contráctil de la musculatura inserta, optimizando el rendimiento del salto al correr, condición vital para especies presas como las gacelas. La falta de analogía de estas respuestas de la estructura peronea a distintos entrenamientos, incompatible con el mantenimiento de un factor de seguridad, sugiere su vinculación preferencial con la optimización de aptitudes esqueléticas con valor selectivo. Esto ampliaría el espectro regulatorio del mecanostato a propiedades esqueléticas 'vitales', más allá del control de la integridad ósea. Su manifestación en el hombre, ajena a connotaciones selectivas (quizá resultante del mantenimiento de genes ancestrales), permitiría proponer la indicación de ejercicios orientados en direcciones preferenciales a este respecto, especialmente cuando estas coincidieran con las de las fuerzas que podrían fracturar al hueso. (AU)

The original notion of the mechanostat as a regulator of bone structural rigidity oriented to maintain a certain 'safety factor' in all skeletons does not seem to correspond equally to every bone and for any type of stimulus. We have discovered that the diaphyseal cortical structure of the human fibula shows an ambiguous behavior of the system, with reference to the use of the foot. The peroneal shaft, in addition to being insensitive to disuse, becomes stiffened, as might be expected, by training in sport disciplines that involve rotating or reversing the foot (hockey, soccer, rugby); but, remarkably, it becomes more flexible in its proximal half by long-distance running training, which optimizes the performance of the jump that accompanies each step. The stiffening would strengthen the peroneal region of insertion of the muscles that rotate or reverse the foot, favoring locomotion on uneven terrain or 'dribbling', typical of predatory species such as leopards. The 'unexpected' proximal flexibilization, despite reducing the resistance to lateral flexion fracture (rare in human), would favor the elastic absorption of contractile energy from the inserted muscles, optimizing jumping performance when running, a vital condition for prey species such as gazelles. The lack of analogy of these responses of the peroneal structure to different training, incompatible with the maintenance of a safety factor, suggests its preferential link with the optimization of skeletal aptitudes with selective value. This would expand the regulatory spectrum of the mechanostat to 'vital' skeletal properties, beyond the control of bone integrity. Its manifestation in humans, oblivious to selective connotations (perhaps resulting from the maintenance of ancestral genes), would make it possible to propose the indication of exercises oriented in preferential directions, especially when they coincide with the direction of the forces that could fracture the bone. (AU)

¿A qué pregunta responde "el hueso"?: una cuestión de direccionalidad estructural y organización biológica (hueso y huesos, del big-bang a la osteoporosis) / To which question is 'bone' the answer?: a matter of structural directionality and biological organization (bone and bones, from the big bang to osteoporosis)

La "razón de ser" de nuestros huesos y esqueletos constituye un dilema centralizado en los conceptos biológicos de "estructura" y "organización", cuya solución necesitamos comprender para interpretar, diagnosticar, tratar y monitorear correctamente las osteopatías fragilizantes. Últimamente se ha reunido conocimiento suficiente para proponer aproximaciones razonables a ese objetivo. La que exponemos aquí requiere la aplicación de no menos de 6 criterios congruentes: 1) Un criterio cosmológico, que propone un origen común para todas las cosas; 2) Un criterio biológico, que explica el origen común de todos los huesos; 3) Un enfoque epistemológico, que desafía nuestra capacidad de comprensión del concepto concreto de estructura y del concepto abstracto de organización, focalizada en la noción rectora de direccionalidad espacial; 4) Una visión ecológica, que destaca la importancia del entorno mecánico de cada organismo para la adecuación de la calidad mecánica de sus huesos a las "funciones de sostén" que les adjudicamos; 5) Una correlación entre todo ese conocimiento y el necesario para optimizar nuestra aptitud para resolver los problemas clínicos implicados y 6) Una jerarquización del papel celular en el manejo de las interacciones genético-ambientales necesario para asimilar todo el problema a una simple cuestión de organización direccional de la estructura de cada hueso. Solo aplicando estos 6 criterios estaríamos en condiciones de responder a la incógnita planteada por el título. La conclusión de esta interpretación de la conducta y función de los huesos debería afectar el fundamento de la mayoría de las indicaciones farmacológicas destinadas al tratamiento de la fragilidad ósea. (AU)

The nature of the general behavior of our bones as weight-bearing structures is a matter of two biological concepts, namely, structure and organization, which are relevant to properly interpret, diagnose, treat, and monitor all boneweakening diseases. Different approaches can be proposed to trace the corresponding relationships. The one we present here involves six congruent criteria, namely, 1) a cosmological proposal of a common origin for everything; 2) a biological acknowledgement of a common origin for all bones; 3) the epistemological questioning of our understanding of the concrete concept of structure and the abstract notion of organization, focused on the lead idea of directionality; 4) the ecological insight that emphasizes the relevance of the mechanical environment of every organism to the naturally-selected adjustment of the mechanical properties of their mobile bones to act as struts or levers; 5) The clinical aspects of all the alluded associations; 6) The central role of bone cells to control the genetics/ environment interactions of any individual as needed to optimize the directionality of the structure of each of his/her bones to keep their mechanical ability within physiological limits. From our point of view, we could only solve the riddle posed by the title by addressing all of these six criteria. The striking conclusion of our analysis suggests that the structure (not the mass) of every bone would be controlled not only to take care of its mechanical ability, but also to cope with other properties which show a higher priority concerning natural selection. The matter would be that this interpretation of bone behavior and 'function' should affect the rationales for most pharmacological indications currently made to take care of bone fragility. (AU)

Demostración original de la interferencia de los efectos modeladores corticales expansivos de un entrenamiento sobre los de otro ulterior: (la modelación 'marca el terreno' para la remodelación) / Original demonstration of the interference of the expansive cortical modeling effects of one training on those of another further training: (modeling "sets limits" for remodeling)

La expansión modeladora de la geometría cortical de un hueso inducida por su entorno mecánico podría ser difícil de modificar por estímulos ulteriores con diferente direccionalidad. Este estudio, que por primera vez combina datos tomográficos del peroné (pQCT) y dinamométricos de la musculatura peronea lateral, intenta demostrar que, en individuos jóvenes no entrenados, el entrenamiento en fútbol produce cambios geométricos peroneos expansivos, similares a los del rugby, que podrían interferir en los efectos de un entrenamiento ulterior direccionalmente diferente (carrera larga). Confirmando la hipótesis, los resultados indican, con evidencias originales, 1) la relevancia creciente del uso del pie (rotación externa y eversión provocadas por los peroneos laterales) para la determinación de la geometría peronea (incremento del desarrollo de los indicadores de masa y de diseño óseos), evidenciada por la secuencia creciente de efectos: carrera < fútbol < rugby; 2) la predominancia de esos efectos sobre el desarrollo centro-proximal del peroné para resistir a la flexión lateral, y en la región distal para resistir el buckling (principal sitio y causa de fractura del hueso) y 3.) la relevancia de la anticipación de esos efectos para interferir en la manifestación de los cambios producidos por un entrenamiento ulterior (carrera), cuando los del primero (fútbol) afectan la modelación cortical de modo expansivo. Esta última deducción demuestra, en forma inédita, que un cambio modelatorio expansivo tempranamente inducido sobre la estructura cortical ósea 'delimitaría el terreno'para la manifestación de cualquier otro efecto ulterior por estímulos de distinta direccionalidad. (AU)

The modeling-dependent, geometrical expansion of cortical bone induced by the mechanical environment could be hard to modify by subsequent stimulations with a different directionality. The current study aimed to demonstrate that in young, untrained individuals, training in soccer or rugby enhances the geometric properties of the fibula cortical shell in such a way that the geometrical changes could interfere on the effects of a second training in which the loads are induced in a different direction, e.g. long-distance running. The original findings reported herein confirm our hypothesis and support 1) The relevance of the use of the foot (external rotation and eversion produced by peroneus muscles) to determine fibula geometry (improved development of indicators of bone mass and design) as evidenced by the increasing nature of the effects induced by running < soccer < rugby trainings; 2) The predominance of those effects on the ability of the fibula to resist lateral bending in the centralproximal region (insertion of peroneus muscles), and to resist buckling in the distal region (the main cause and site of the most frequent bone fractures), and 3) The interaction of the effects of a previous training with those of a subsequent training with a different orientation of the loads when the former induced a modeling-dependent expansion of the cortex. Our results support the proposed hypothesis with original arguments by showing that a first, expansive effect induced on cortical bone modeling would set the stage the manifestation of any subsequent effect derived from mechanical stimuli. (AU)

Golden mussel (Limnoperna fortunei) in feed for broiler chicks using tannin as a sequestrant of toxic metals / Mexilhão dourado (Limnoperna fortunei) na alimentação de pintos de corte utilizando tanino como sequestrante de metais tóxicos

This study aimed to evaluate the use of wattle tannin as an adsorbent of toxic metals in broilers fed on diets with different levels of replacement of limestone with golden mussel meal. First, we conducted a trial to evaluate the performance of broiler chicks from 1 to 21 days old when fed on wattle tannin. For this we used 720 male broiler chicks that were one day old, in a completely randomized design with six treatments and six replications. The treatments were composed of basal diets with increasing levels of wattle tannin (0, 250, 500, 750, 1000 and 1250 g tonne-1), where the tannin replaced the inert material of the feed. All of the diets were isonutritive and isocaloric. The results showed that 250 g tonne-1 of tannin was detrimental to weight gain, final weight and feed conversion, and the use of 1000 g tonne-1 of wattle tannin, in addition to these effects, caused a drop in consumption of the ration. There was no effect of treatment on morphometric measurements of villi, crypt or the villus:crypt ratio. Next, we conducted a second test to evaluate the performance of broiler chicks from 1 to 21 days of age when fed with increasing levels of replacement (0, 25, 50, 75, 100%) of limestone with golden mussel and even supplementation or not wattle tannin. Five repetitions were used and the birds were housed in a completely randomized design. In diets with the inclusion of tannin, 250 g tonne-1 of wattle tannin was used, which replaced the inert material in the feed. In this test, 1200 male broiler chicks that were one day old were used. The results showed that the golden mussel contains large quantities of calcium, with low concentrations of toxic metals and microbiological contamination within the allowed range. Performance data show that mussel can be used to replace up to 100% of limestone in feed without affecting the variables, but the use of 250 g tonne-1 of wattle tannin affects the performance of chicks. [...](AU)

Este estudo teve como objetivo avaliar a utilização de tanino de acácia como adsorvente de metais tóxicos em rações para pintos de corte alimentados com diferentes níveis de inclusão da farinha de mexilhão dourado em substituição ao calcário calcítico. Primeiramente foi realizado um ensaio para avaliar o desempenho de pintos de corte de 1 a 21 dias, alimentados com tanino de acácia, utilizandose 720 pintos de corte, machos, com um dia de idade, distribuídos em delineamento inteiramente casualizado, com seis tratamentos e seis repetições. Os tratamentos foram formados por rações basais com níveis crescentes de tanino de acácia (0, 250, 500, 750, 1000, 1250 g ton-1 de tanino de acácia), onde o mesmo substituiu o material inerte da ração, sendo todas as dietas isonutritivas e isoenergéticas. Os resultados apontaram que 250 g ton-1 de tanino foi prejudicial para ganho de peso, peso final e conversão alimentar, ao passo que, a utilização de 1000 g ton-1 de tanino de acácia, além destes efeitos citados causou queda no consumo de ração. Para as medidas morfometricas de vilo, cripta e relação vilo:cripta, não houve efeitos dos tratamentos. Na sequência foi realizado um segundo ensaio para avaliar o desempenho de pintos de corte de 1 a 21 dias de idade com níveis crescentes de substituição (0; 25; 50; 75; 100%) do calcário calcítico pelo mexilhão dourado e ainda a suplementação ou não de tanino de acácia, com 5 repetições, as aves foram alojadas em delineamento inteiramente casualizado. Nas dietas com a inclusão de tanino utilizou-se 250 g ton-1 de tanino de acácia, o qual foi substituto do material inerte da ração. Foram utilizados neste ensaio 1200 pintos de corte, machos, com um dia de idade. Os resultados mostraram que o mexilhão dourado possui grande quantidade de cálcio, com baixas concentrações de metais tóxicos e contaminação microbiológica dentro da permitida. [...](AU)

Golden mussel (Limnoperna fortunei) in feed for broiler chicks using tannin as a sequestrant of toxic metals / Mexilhão dourado (Limnoperna fortunei) na alimentação de pintos de corte utilizando tanino como sequestrante de metais tóxicos

This study aimed to evaluate the use of wattle tannin as an adsorbent of toxic metals in broilers fed on diets with different levels of replacement of limestone with golden mussel meal. First, we conducted a trial to evaluate the performance of broiler chicks from 1 to 21 days old when fed on wattle tannin. For this we used 720 male broiler chicks that were one day old, in a completely randomized design with six treatments and six replications. The treatments were composed of basal diets with increasing levels of wattle tannin (0, 250, 500, 750, 1000 and 1250 g tonne-1), where the tannin replaced the inert material of the feed. All of the diets were isonutritive and isocaloric. The results showed that 250 g tonne-1 of tannin was detrimental to weight gain, final weight and feed conversion, and the use of 1000 g tonne-1 of wattle tannin, in addition to these effects, caused a drop in consumption of the ration. There was no effect of treatment on morphometric measurements of villi, crypt or the villus:crypt ratio. Next, we conducted a second test to evaluate the performance of broiler chicks from 1 to 21 days of age when fed with increasing levels of replacement (0, 25, 50, 75, 100%) of limestone with golden mussel and even supplementation or not wattle tannin. Five repetitions were used and the birds were housed in a completely randomized design. In diets with the inclusion of tannin, 250 g tonne-1 of wattle tannin was used, which replaced the inert material in the feed. In this test, 1200 male broiler chicks that were one day old were used. The results showed that the golden mussel contains large quantities of calcium, with low concentrations of toxic metals and microbiological contamination within the allowed range. Performance data show that mussel can be used to replace up to 100% of limestone in feed without affecting the variables, but the use of 250 g tonne-1 of wattle tannin affects the performance of chicks. [...]

Este estudo teve como objetivo avaliar a utilização de tanino de acácia como adsorvente de metais tóxicos em rações para pintos de corte alimentados com diferentes níveis de inclusão da farinha de mexilhão dourado em substituição ao calcário calcítico. Primeiramente foi realizado um ensaio para avaliar o desempenho de pintos de corte de 1 a 21 dias, alimentados com tanino de acácia, utilizandose 720 pintos de corte, machos, com um dia de idade, distribuídos em delineamento inteiramente casualizado, com seis tratamentos e seis repetições. Os tratamentos foram formados por rações basais com níveis crescentes de tanino de acácia (0, 250, 500, 750, 1000, 1250 g ton-1 de tanino de acácia), onde o mesmo substituiu o material inerte da ração, sendo todas as dietas isonutritivas e isoenergéticas. Os resultados apontaram que 250 g ton-1 de tanino foi prejudicial para ganho de peso, peso final e conversão alimentar, ao passo que, a utilização de 1000 g ton-1 de tanino de acácia, além destes efeitos citados causou queda no consumo de ração. Para as medidas morfometricas de vilo, cripta e relação vilo:cripta, não houve efeitos dos tratamentos. Na sequência foi realizado um segundo ensaio para avaliar o desempenho de pintos de corte de 1 a 21 dias de idade com níveis crescentes de substituição (0; 25; 50; 75; 100%) do calcário calcítico pelo mexilhão dourado e ainda a suplementação ou não de tanino de acácia, com 5 repetições, as aves foram alojadas em delineamento inteiramente casualizado. Nas dietas com a inclusão de tanino utilizou-se 250 g ton-1 de tanino de acácia, o qual foi substituto do material inerte da ração. Foram utilizados neste ensaio 1200 pintos de corte, machos, com um dia de idade. Os resultados mostraram que o mexilhão dourado possui grande quantidade de cálcio, com baixas concentrações de metais tóxicos e contaminação microbiológica dentro da permitida. [...]

Structural differences in cortical shell properties between upper and lower human fibula as described by pQCT serial scans. A biomechanical interpretation.

This study describes the structural features of fibula cortical shell as allowed by serial pQCT scans in 10/10 healthy men and women aged 20-40years. Indicators of cortical mass (mineral content -BMC-, cross-sectional area -CSA-), mineralization (volumetric BMD, vBMD), design (perimeters, thickness, moments of inertia -MIs-) and strength (Bone Strength Indices, BSIs; polar Strength-Strain Index, pSSI) were determined. All cross-sectional shapes and geometrical or strength indicators suggested a sequence of five different regions along the bone, which would be successively adapted to 1. transmit loads from the articular surface to the cortical shell (near the proximal tibia-fibular joint), 2. favor lateral bending (central part of upper half), 3. resist lateral bending (mid-diaphysis), 4. favor lateral bending again (central part of the lower half), and 5. resist bending/torsion (distal end). Cortical BMC and the cortical/total CSA ratio were higher at the midshaft than at both bone ends (p<0.001). However, all MIs, BSIs and pSSI values and the endocortical perimeter/cortical CSA ratio (indicator of the mechanostat's ability to re-distribute the available cortical mass) showed a "W-shaped" distribution along the bone, with maximums at the mid-shaft and at both bone's ends (site effect, p<0.001). The correlation coefficient (r) of the relationship between MIs (y) and cortical vBMD (x) at each bone site ("distribution/quality" curve that describes the efficiency of distribution of the cortical tissue as a function of the local tissue stiffness) was higher at proximal than distal bone regions (p<0.001). The results from the study suggest that human fibula is primarily adapted to resist bending and torsion rather than compression stresses, and that fibula's bending strength is lower at the center of its proximal and distal halves and higher at the mid-shaft and at both bone's ends. This would favor, proximally, the elastic absorption of energy by the attached muscles that rotate or evert the foot, and distally, the widening of the heel joint and the resistance to excessive lateral bending. Results also suggest that biomechanical control of structural stiffness differs between proximal and distal fibula.

Bone histomorphometry: a concise review for endocrinologists and clinicians / Histomorfometria óssea: uma revisão concisa para endocrinologistas e clínicos

Bone histomorphometry is a quantitative histological examination of an undecalcified bone biopsy performed to obtain quantitative information on bone remodeling and structure. Labeling agents taken before the procedure deposit at sites of bone formation allowing a dynamic analysis. Biopsy is indicated to make the diagnosis of subclinical osteomalacia, to characterize the different forms of renal osteodystrophy and to elucidate cases of unexplained skeletal fragility. Bone histomorphometric parameters are divided into structural and remodeling subgroups, with the latter being subdivided into static and dynamic categories. Metabolic bone disorders such as osteomalacia, hyperparathyroidism, hypothyroidism, osteoporosis and renal osteodystrophy display different histomorphometric profiles. Antiresorptive and anabolic drugs used for the treatment of osteoporosis also induce characteristic changes in the bone biopsy. Bone histomorphometry is an important research tool in the field of bone metabolism and provides information that is not available by any other investigative approach.

Histomorfometria óssea é uma avaliação histológica quantitativa de uma biópsia óssea calcificada realizada para obter informação sobre a remodelação e a estrutura óssea. Uma análise dinâmica é possível quando substâncias que fazem a marcação do osso são tomadas antes do procedimento e se depositam no local de formação óssea. A biópsia é indicada para diagnóstico de osteomalácia, diferentes formas de osteodistrofia renal e nos casos não explicados de fragilidade esquelética. O preparo e a análise das amostras necessitam de um laboratório especializado. A histomorfometria avalia parâmetros estruturais e de remodelação óssea, sendo o último subdividido em estático e dinâmico. Doenças osteometabólicas como osteomalácia, hiperparatireoidismo, hipoparatireoidismo, osteoporose e osteodistrofia renal apresentam parâmetros histomorfométricos distintos. Medicações antirreabsortivas e anabólicas usadas no tratamento da osteoporose também induzem alterações características na biópsia óssea. A histomorfometria óssea é uma ferramenta importante no metabolismo ósseo e oferece informação que não é possível por nenhum outro método diagnóstico.